Linkage system for trenching machine



, p i 22, 1958 w. w. EVERTT I 2,831,273

LINKAGE SYSTEM FOR TRENCHING MACHINE Filed July 25, 1956 INVENTOR. wooazow w. EVE/2577' MAM ATMRNEY.

Unite Woodrow W. Everett, Phoenix, Ariz., assignor to The Earth Equipment Corp, Los Angeles, Calif.

Application July 23, 1956, Serial No. 599,395

3 tClaims. (Cl. 37-86) This invention pertains to excavating machines and is particularly directed to trenching and ditching machines employing a supporting frame and an endless bucket chain line or endless digger unithaving a series of excavating buckets mounted on an ordinary tractor.

This application is related to copending applications Serial No, 198,617, filed December 1, 1950, and now abandoned, and Serial No. 218,822, filed April 2, 1951, and now abandoned.

One of the objects of this invention is to provide an improved linkage system for supporting and manipulating the bucket chain line frame or endless digger unit on an ordinary tractor.

Another object of this invention is to provide an improved linkage system in which an extensible and retractable power actuator provides the sole means for raising and lowering the bucket chain line digger unit relative to the ground surface and for positively and accurately positioning and holding the digger unit relative to the tractor upon which it is mounted.

Further features and advantages of this invention will appear from a detailed description of the drawings in which:

The figure is a diagram showing all of the essential elements of the linkage system for a trenching machine incorporating the features of this invention.

As an example of one embodiment of this invention, there is shown a tractor having a frame and the usual rear driving Wheels 11 which contact the ground surface 12 and may be traversed along the ground by the usual engine and transmission of the tractor. An upper lever arm or stabilizer arm 13 is pivotally mounted at its inner end at 14 on the frame 10 while at the other outer end of the upper arm 13 is pivotally mounted at 15 the bucket chain line frame or endless digger unit 16 which may have the usual endless chain 17 upon which is carried the digging buckets 13.

A lower lever arm or stabilizer arm 19 has its inner end pivotally mounted at 29 on the frame 14 of the tractor while the other outer end of the arm 19 is pivotally connected at 21 to a sliding connection member 22.

The sliding connection member 22 has a suitable guide-.

way slot 23 slidingly engaging a mating guide flange 24 fixed on the bucket chain line frame 16 so that the frame 16 may slide up and down relative to the outer end of the lower lever arm 19. it is to be clearly noted that the bucket chain line frame 16 is rigidly heldby the sliding connection member 22 so that the frame 16 has no relative movement to or from the outer end of the lower lever arm 19. In other words, the bucket chain line frame is under positive control of the traverse movement of the tractor so that accurate positioning of the digger bucket teeth 25 may be had at all times. Thus, positively controlled precise digging in either direction up to obstructions such as foundations, pipe lines, and the like, is obtained since there is no free swinging of the bucket chain line frame 16 relative to the-tractor during the digging operations.

rates Patent U ln order to raise and lower the bucket chain line frame 16 to and from retracted road traveling positionand for regulating the depth of the trench to be cut, there is provided an extensible and retractable power actuator intermediate point on the upper lever arm 13. Thus,

by appropriately energizing the actuator the outer ends 15 and 21 of the respective lever arms 13 and 19 may be moved to and from each other, the bucket chain line.

frame 16 sliding at 23-24 in the sliding connection member 22 as described. Up to this point the apparatus described is identical to that set forth in application Serial Number 218,822 cited above.

However, in the instant application the depth or profile control is obtained solely by the appropriate energizationof the actuator without the use of any stop means or other restraining device interacting between the tractor frame 19 and the lower lever arm 19 as in application Serial Number 218,822. This new mode of operation and new linkage system is brought about by providing a rigid link 29 which is pivotally mounted at its lower end at the point 30 on the lower lever arm, intermediate the pivotal connection 21 of the sliding connection member on the outer end of the lower lever arm 1'9 and the pivotal connection 27 of the actuator 26 with that arm. The upper other end of the link 29 is pivotally mounted at 31 on the upper lever arm 13, the point-31' being located intermediate the pivotal connection 14 01 the upper arm 13 with the tractor frame and the pivotal connection 2 of the actuator 26 with upper arm 13. i

By such structure no longer is: the lower lever 'arm limited to a fixed down position and held there by the weight of the upper lever arm and bucket chain line frame while only the upper lever arm is raised and lowered for the entire travel of the linkage whenever the actuator 26" is energized. Further, the outer ends 15 and 22 of'the arms are positively controlled to move at a predetermined differential rate of relative movement to and from each other when the actuator 26 is appropriately'energizedso that precise profie depth control is obtained together with the ability to move the bucket chain line up to road traveling position all by the sole use of the actuator 26. The only connection between the instant linkage system and the tractor frame 10 is at the points 14 and 20, the entire linkage system being self-contained and rendered fully operative by the critical positioning of the actuator 26 and the link 29 as described.

While the apparatus herein disclosed and described constitutes a preferred form of the invention, it is also to be understood that the apparatus is capable of mechanical alteration without departing from the spirit of the invention and that such mechanical arrangement and commercial adaptation as fall within the scope of the appendant claims are intended to be included herein.

Having thus fully set forth and described this invention what is claimed and desired to be obtained by United States Letters Patent is:

1. In a linkage system for a trenching machine having a frame, the combination comprising an outwardly extending upper stabilizer arm pivotally supported at its inner end to said frame, an outwardly extending lower stabilizer arm pivotally supported at its inner end to said frame at a point lower than the pivot of the upper stabilizer arm, means pivotally connected to the upper tabilizer arm and to the lower stabilizer arm at locations spaced from their pivoted ends for applying a spreading Patented Apr. 22, i

&

force between the two arms, the linear distance between the pivoted inner end of the upper stabilizer arm and its connection with the spreading means being greater than the corresponding distance related to the lower stabilizer arm, an endless digger unit disposed at the outer ends of the upper and lower stabilizer arm, means pivotally connecting the digger unit to the upper stabilizer arm, and means slidably and pivotally coupling the digger unit to the lower stabilizer arm so that relative movement between the digger unit and the lower stabilizer arm is permitted in a vertical direction, and a rigid link pivotally connected to the upper stabilizer arm and to the lower stabilizer arm at locations spaced from their pivoted ends to limit said relative vertical movement between said digger unit and said lower stabilizer arm to a predetermined rate of relative movement therebetween, so that said link and said spreading means provide the sole means for controlling movement of said digger unit from digging to retracted road travel position.

2. In a linkage system for a trenching machine having a frame, the combination comprising an outwardly extending upper stabilizer arm pivotally supported at its inner end to said frame, an outwardly extending lower stabilizer arm pivotally supported at its inner end to said frame at a point lower than the pivot of the upper stabilizer arm, means pivotally connected to the upper stabilizer arm and to the lower stabilizer arm at loca tions spaced from their pivoted ends for applying a spreading force between the two arms, the linear distance between the pivoted inner end of the upper stabilizer arm and its connection with the spreading means being greater than the corresponding distance related to the lower stabilizer arm, an endless digger unit disposed at the outer ends of the upper and lower stabilizer arm, means pivotally connecting the digger unit to the upper stabilizer arm, and means slidably and pivotally coupling the digger unit to the lower stabilizer arm so that relative movement between the digger unit and the lower stabilizer arm is permitted in a vertical direction, and a rigid link pivotally connected at its lower end to the lower stabilizer arm at a point intermediate said slidable and pivotal coupling and the pivotal connection of said spreading force means on said lower stabilizer arm and pivotally connected to said upper stabilizer arm at a point intermediate the pivotal connection of said upper stabilizer arm on said frame and the pivotal connection of said spreading force means with said upper stabilizer arm, said link being adapted tolimit said relative vertical movement between said digger unit and said lower stabilizer arm to a predetermined rate of relative movement therebetween, so that said link and said spreading means provide the sole means for controlling movement of said digger unit from digging to retracted road travel position.

3. In a linkage system for a trenching machine having a frame, an upper lever arm, a pivotal connection between one end of said upper lever arm and said frame, a bucket chain line frame, a pivotal connection between the other end of said upper lever arm and the upper end of said bucket chain line frame, a lower lever arm, a pivotal connection between one end of said lower lever arm and said frame, a sliding connection member, means for pivotally mounting said sliding connection member on the other end of said lower lever arm, a guide flange on said bucket chain line frame slidingly engaged and supported in said sliding connection member, an extensible and retractable power actuator, a pivotal connection between one end of said power actuator and an intermediate point on the lower lever arm, and a pivotal connection between the other end of said power actuator and an intermediate point on the upper lever arm, the distance between the intermediate pivotal connection of the other end of said power actuator on the upper lever arm and the pivotal'connection of the upper lever arm and the bucket chainline frame being less than the distance between the intermediate pivotal connection of the one end of said power actuator on the lower lever arm and the pivotal-sliding connection of the lower lever arm and the bucket chain line frame, and a rigid link pivotally mounted on its lower end on said lower lever arm intermediate the pivotal connection of said pivotal-sliding connection member on the outer end of said lower lever arm and the pivotal connection of said power actuator on said lower lever arm, and said rigid link being pivotally mounted at its upper end on the upper lever arm at a point intermediate the pivotal connection of the upper lever arm with the tractor frame and the pivotal connection of said actuator on said upper lever arm, said power actuator and link providing the sole means for profile control positioning of said bucket chain line frame and for moving said bucket chain line frame to and from road traveling position.

References Cited in the file of this patent UNITED STATES PATENTS 1,762,568 Barber June 10, 1930 1,762,569 Barber June 10, 1930 2,391,224 Carter Dec. 18, 1945 

